Exam 1 Flashcards
Features between two or more organisms are ______ if they share common ancestry
Homologous
Features of two or more organisms are ____ if they only share a common function
Analogous
A term that means similar in structure AND origin
Homology
Structures can be 1.) _____, 2.) _____, or 3.) ______.
Homologous Analogous Both
Retention by an organism of juvenile or larval traits later into life
Paedomorphosis
When certain characteristics possessed by a former ancestor are lost
Degeneration
_____ characteristics are held by lower forms
Primitive
A characteristic found in higher vertebrates in the phylogenetic tree
Advanced
Higher vertebrates with an amniotic sac
Amniotes
Lower vertebrates without an amniotic sac
Anamniotes
The membrane sac that surrounds the embryo
Amnion
Features found within a specific group
Specialized
A structure in the body of an organism with no apparent function - it may have had a function at one time but through years of evolution the function was lost
Vestigial
Structures are _____ ______ if they occupy different spatial positions in a series of similar structures (in the same animal)
Serially Homologous
Structures are _______ ________ if they develop from equivalent embryonic primordia, but are dimorphic
Sexually Homologous
Erect and facing the observer, arms at sides, palms of the hands turned forward so the radius and ulna do not cross
Anatomical Position
Toward the head or the upper part of a structure (3 Terms)
Superior/Cephalad/Craniad
Away from the head or toward the lower part of a structure (2 Terms)
Inferior/Caudad
Nearer to or at the front of the body (2 Terms)
Anterior/Ventral
Nearer to or at the back of the body (2 Terms)
Posterior/Dorsal
Nearer the midline of the body or a structure (1 Term)
Medial
Farther from the midline of the body or a structure (1 Term)
Lateral
Between two structures (1 Term)
Intermediate
Nearer the attachment of an extremity to the trunk or a structure (1 Term)
Proximal
Farther from the attachment of an extremity to the trunk or a structure (1 Term)
Distal
Toward or on the surface of the body (1 Term)
Superficial
Away from the surface of the body (1 Term)
Internal
Pertaining to the outer wall of a body cavity (1 Term)
Parietal
Pertaining to the covering of an organ (1 Term)
Visceral
Imaginary flat surfaces that pass through the body
Planes
A plane that runs vertically
Sagittal
A plane that runs through the midline of the body, runs vertically and divides the body or organs into equal right and left sides
Midsagittal
A plane that runs vertically, but divides the body or organs into unequal left and right portions
Parasagittal
A plane that runs vertically and divides the body or organs into anterior/posterior
Frontal/Coronal Plane
A plane that runs parallel to the ground and divides the body or organs into superior/inferior portions
Horizontal/Transverse Plane
A cavity containing the brain
Cranial
A cavity containing the spinal cord and the beginnings of spinal nerves
Vertebral
The chest cavity. contains the ____, ______, and _____ cavities.
Thoracic; Pleural, Pericardial, Mediastinum
Cavity surrounding the lungs, the serous membrane is the pleura
Pleural
Cavity surrounding the heart; the serous membrane of this cavity is the pericardium
Pericardial
The central portion of the thoracic cavity between the lungs, extends from sternum to vertebral column and from neck to diaphragm; contains heart, thymus, esophagus, trachea, and several large blood vessels
Mediastinum
What are the subphyla of Phylum Chordata
Urochordata Cephalochordata Vertebrata
Animals that have a notochord in the embryo stage at least
Chordates
What are the big 4 morphological characteristics of chordates?
- Notochord
- Hollow dorsal nerve cord
- Perforated pharynx
- Post-anal tail
Name other characteristics of chordates
- Bilateral symmetry
- Cephalization
- Metamerism/segmentation
- True body cavity or coelom
- Triploblastic germ layers
- Blastopore becomes anus (Deuterostome)
- True endoskeleton
- Presence of ventrally located heart
Longitudinal rod of support tissue that is derived from the dorsal wall of the embryonic gut
Notochord
Who retains the notochord as adults?
Cephalochordates and many vertebrates
What is the location of the notochord?
Immediately ventral to the CNS, dorsal to the alimentary canal, extending from midbrain to the tip of the tail
Muscular proboscis with a small organ in hemichordates
Homolog of the notochord
Where does the dorsal hollow nerve cord derive from? How?
Ectoderm; Neuralation
What does the hollow central nervous system consist of?
A brain, spinal cord, and central lumen (neurocoel)
Extended anterior portion of the gut, perforated by numerous slits and can allow water taken into the mouth to be passed out of the body
Perforated pharynx
This separates adjacent pharyngeal - another name for gill arch
Pharyngeal arch
Circulatory system in cephalochordates where the heart pumps blood. Name the type of heart and list blood flow
Ventral heart; forward into a ventral aorta, up through aortic arches, into a dorsal aorta
Principle sense and nervous organs are concentrated in the head region
Cephalization
What subphyla has no head?
Urochordates
Segmentation of some features of the body
Metamerism
Three deuterostomes
Phylum Echinodermata Phylum Hemichordata Phylum Chordata
Balanoglossus and Dolichoglossus are tongue worms in the Phylum ______
Hemichordata
Name the division of Phylum Chordata and list their respective names
Urochordata - tunicates Cephalochordata - amphioxus Vertebrata
Name the classes of Phylum Vertebrata. If they are extinct, indicate so.
Agnatha Placodermi (Extinct) Chrondrichthyes Amphibia Reptilia Aves Mammalia
What is the name of the notochord homolog in hemichordates?
Stomochord
A short diverticulum of the foregut, which extends forward into the proboscis
Stomochord
________ have vertebrate-type pharyngeal gill slits and a larvae called tornaria that’s bilaterally symmetrical.
Hemichordates
Describe the circulatory and reproductive systems of hemichordates
Circulatory - dorsal and ventral longitudinal vessel Reproductive - segmented series of gonads
What are the two groups of extant non-vertebrate chordates?
Urochordate and cephalochordate
The larval form of urochordates may represent a starting point for the evolution of _____.
Vertebrates
_______ may have lifestyles similar in some ways to those of the earliest vertebrates.
Cephalochordates
Nonvertebrate chordates that are both small marine animals
Urochordates and Cephalochordates
What is the common name of urochordates?
Tunicates
Describe the characters of adult urochordates?
Shaped like sacs/stalks, sessile, body covered by tunics
What types of feeders are adult urochordates?
Filter
Where is the atrium in adult urochordates?
Between the tunic and pharynx
In adult urochordates, food is trapped in a sticky mucus that moves from the ____ to pharyngeal bars, and then to the ______.
Endostyle; Esophagus
In what stage do urochorates moreso resemble vertebrates?
Larval
Where is the notochord located in larval urochordates?
The tail
What am I? Has pharynx with gill slits, post-anal tail, and larval stage lasts two days
Larval urochordate
What is the best known cephalochordate? Give the common and Latin name
Amphioxus Branchiostoma lanceolatum
Name the primitive characteristics of Branchiostoma lancelatum
- Nephridia
- Pigmented eye spot
- No heart
- Epidermis one cell thick
- Segmented musculature
- Notochord
Name the specialized characteristics of Branchiostoma lancelatum
Notochord extends anterior to brain Atrium and metapleural folds Feeding apparatus
Blocks of striated muscle fibers arranged on both sides of the body separated by sheets of connective tissue. Found in cephalochordates as well as urochordate larvae.
Myomeres
What are these?

Metapleural folds
In amphioxus, the notochord extends the full length of the body, prevents the body from _____ when the _____ contract, and extends from the tip of the snout, to the end of the tail, going beyond the region of ______.
Shortening; Myomeres; Myomeres
What are the pharynx and gill slits used for in amphioxus?
Filter feeding
How do cephalochordates breathe? What is the major difference between cephalochorates and vertebrates?
Through the skin
Vertebrates use the pharynx and gill slites for respiration
Name the parts of the Amphioxus:
- Attached to the margin of the oral hood; filters out large particles
- Ciliated tracts, some food particles are entrapped and sent back to the pharynx
- Screens food particles (Velar Tentacles)
- Buccal cirri
- Wheel organ
- Velum
Describe the circulatory system of cephalochordates
No true heart, no red/white blood cells, there’s a ventral pump located behind the gill slits that powers circulation ventral to dorsal through the gill arches
Describe the nervous system of cephalochordates
Hollow dorsal nerve cord and no true brain
What make up the excretory system in cephalochordates? They are a part of the nephrons in vertebrates
Solenocytes/Podocytes
An important difference is that the excretory organs of cephalochordates are derived from _____ instead of _____ (as in vertebrates).
Ectoderm; Mesoderm
Instead of a true liver, what do cephalochordates have?
Hepatic diverticula (midgut cecum)
Wehere does the atrium of cephalochordates open to?
The outside through the atriopore
Name the triploblastic germ layers of vertebrates
- Ectoderm - outside
- Mesoderm - middle
- Endoderm - inside
Part of the vertebrate body that is lined by the mesoderm
Body cavity/Coelom
Define a complete gut
There are separate openings for the mouth and the anus
In vertebrates, where does the anus derive from?
Blastopore
In vertebrates, where does the internal skeleton derive from?
Mesoderm
What does mesoderm in vertebrates form from?
Tissue in the embryonic gut
What do vertebrates have in common with adult urochordates? Larval urochordates?
- Pharyngeal gill slits
- The big four characteristics
What are the shared characters of vertebrates and cephalochordates?
- True somites/myotomes
- Certain mesoderm specialization
- Development of various neural tissue by the notochord
- A caudal (tail) fin fold
- Ventral to dorsal pattern of blood circulation
- Excretory tissue formed from specialized cells (podocytes)
In vertebrates, muscle blocks are usually called ____, rather than _____ or myomeres.
Somites; Myotomes
Only vertebrates have a true ____, ____ structure, and ____ that supports and protects the _____.
Brain; Skeletal; Cranium; Brain
Sense organs of vertebrates
Eyes, ears, and olfactory organs
Name the unique characters of vertebrates
- Hepatic portal system
- Gall bladder
- Pancreas
- Spleen
- Heart with chambers
What is the function of the perforated pharyx in vertebrates?
Respiratory
Describe the most distinct and important new feature observed in early vertebrates
Head with tripartite brain inside cartilaginous cranium - included sense organs
Instead of cilia, what did early vertebrates use to move water over gill bars? How did they use the water?
Pharyngeal musculature; Respiration
Where did bony tissue form in early vertebrates as a kind of exoskeleton?
Skin
Agnathan
A jawless vertebrate
Gnathostome
Vertebrate with jaws
Vertebrate with (or had) four legs
Ex: Amphibian
Tetrapod
What permitted egg-laying on land and prevented dessication of the embryo in early vertebrates?
The amniotic sac - specialized membrane around the embryo
Name the classes of fish, state if they are extinct
- Agnatha
- Placodermi - extinct
- Chondrichthyes
- Acanthodii - extinct
- Osteichthyes
Name the subclasses of Agnatha (vertebrate without jaws) and give examples
- Myxinoidea
- Hagfish
- Cephalaspidomorpha
- Ostracoderms - extinct
- Lamprey
Name the subclasses of Chondrichthyes (cartilaginous fish) and give examples
- Elasmobranchi
- Sharks
- Rays
- Holocephali
- Chimaeras
Name the subclasses of Osteichthyes (bony fish) and give examples
- Actinopterygii (ray finned)
- Chondrostei
- Bichirs
- Sturgeons
- Paddlefish
- Neopterygii
- Gars
- Bowfins
- Teleosts
- Chondrostei
- Sarcopterygii (lobe finned)
Coelacanths
Lungfish
Lampreys and hagfish are a group of agnathans called _____.
Cyclostomes
_______, larvae of the lamprey, have the most primitive body plan of living vertebrate.
Ammocoetes
What are some features Agnathans lack when compared with the typical higher vertebrate?
- Jaws
- True teeth, girdles, appendages
- pelvic fins
- Gills are in pouches
______ are the earliest vertebrates.
Ostracoderms
Persistent notochord, lack of complete vertebrae, lack of paired appendages, lack of jaws, and semi-parasitic to bony fishes all describe who?
Agnathans
What is the skeleton of Agnathans like?
Cartilaginous
Who am I?
- Exclusively marine
- No bone
- Body fluids are isosmolal to seawater (have to live in seawater)
Myxinoidea (Hagfish)
When food reaches the gut in _____, it is surrounded by a mucous-like bag secreted by the _____ ______. The membrane allows ______ _____ in and digested food out. The membrane is excreted as a neat wrapper around the feces.
Myxinoidea; gut wall; digestive enzymes
What is the amount range of external gill openings amongst the genera and species of hagfish? Do they correspond to the number of internal gills?
1-15; No
What types of hearts do hagfish have?
A heart near the gills and an accessory heart
What order is the lamprey?
Petromyzontia
How do ammocoetes become adults?
Metamorphosis
What was the most important evolutionary adaptation common to all the rest of the fish? Second most?
Enlargement and adaptation of te first gill arch to function as jaws; paired appendages
What are the classes of jaw bearing fishes? Name if they are extinct
- Placodermii - extinct
- Acanthodii - extinct
- Chondrichthyes
- Osteochthyes
Who am I?
- The first jawed fish
- Among the first with paired appendages
- Persistent notochord
- Some bone
- Among first to have gas bladders
Placodermi
Who am I?
- Spiny fish
- Bone and cartilage in the skeleton
- Large operculum covers gill slits
Acanthodii
Who am I?
- Bone only in scales/teeth
- Cartilaginous
- Solid braincase
- Branching pattern of blood vessels associated with gills
- Small tooth-like scales or none at all
- Appeared about 30 million years later tha nbony fish
Chondrichthyes
What are the subclasses of Chondrichthyes?
- Elasmobranchii
- Holocephali
Who am I?
- Slit-like external gill openings
- First gill slit reduced to roundish opening
- Gill slits are naked
- Small abrasive scales
- Mouth is ventral
- Sharks/rays
Elasmobranchii
What is the roundish opening on Elasmobranchii?
Spiracle
In Elasmobranchii, what is it mean when it is said that the gil slits are naked?
There is no Operculum
Who am I?
- Chiameras
- Atypical group
- Only cartiliginous fish with operculum covering gills
- Notochord persistent
- No spiracle
Holocephali
What am I?
- Skeleton composed primarily of bone
- Bony operculum present
- Gas fille swim bladder present
- 5 gill openings max
- Ry or Lobe finned
Osteichthyes
Neopterygii and Chondrostei are what kinds of fish
Ray finned - Actinopterygii
Dipnoi and Crossopterygii are what kinds of fish
Lobe finned - Sarcopterygii
Who am I?
- Lungfish
- Atypical internal nares (nostrils opening into the mouth)
- Advanced circulatory systems
Dipnoi
Who am I?
- Living fossil
- Thought to be extinct until coelacanth discovered
Crossopterygii
Spaces that surround the heart, lungs, digestive system, and certain urogenital organs
Coelemic cavities
Where do true coelemic cavities occur?
Tissues of mesodermal regions
What is the function of a coelomic cavity?
Provide room for internal organs to moe around and change their relative size as needed
What is the purpose of serous membranes?
Secrete fluid to lubricate the organs
______ membranes cover the inside of body walls and covers the viscera.
Serous
These extend across the coelom from body wall to viscera; they also support internal organs and are a common site of fat storage in mammals
Mesenteries
This joins organ to organ in the ceolom
Omenta / Omentum
The split portions of mesoderm; It wedges down between ectoderm and the archenteron to help form coelomic spaces
Epimere/Mesomere/_____
Hypomere
When the coelom forms, it splits the hypomere into an inner _____ layer and an outer _____ layer
Splanchnic; Somatic
What happens as the coelom gets larger?
The right and left splanchnic layers form either mesentery, omentum, or cover the gut tube and its derivatives
Give examples of the gut tube and its derivatives
Liver, Pancreas
What is the dorsal mesentery?
Where splanchnic layers come together dorsal to the gut
What is the ventral mesentery?
Where splanchnic layers come together ventral to the gut
What happens to the ventral mesentery in humans?
It almost completely disappears, creating a large coelomic space
The ______ mesentery persists between the liver and stomach to form the ______ ______
Ventral; Lesser Omentum
Which vertebrates retain the most of the ventral mesentery
Lungfish and Eels
This persists almost entirely in humans and supports the gut in the body cavity
Example: Mesocolon - holds the colon in place
Dorsal mesentery
Where does the Greater Omentum develop from in mammals?
Dorsal mesentery
Although the dorsal mesentery mostly remains in other vertebrates (besides humans), what’s wrong?
It’s usually incomplete and variable
For hagfish, larval lamprey, and a few other fish:
A ____ _____ extends part og the way up from the ventral body wall ______ to the heart, partly separating an anterior ______ cavity from a larger _________ cavity.
- Transverse septum
- Posterior
- Pericardial
- Pertoneal
There is a complete pericardium in vertebrates, excluding ____, ____ ____, and other fish.
- Hagfish
- Larval Lamprey
In most vertebrates, the _____ _____ completely separates the heart from the principal coelom - which is now called the ______ cavity because lungs are present.
- Transverse Septum
- Pleuroperitoneal
Where does the liver start to grow in tetrapods? What does it grow into, and separate from almost completely?
- Transverse Septum
- (Grows into) Ventral Mesentery
- (Separates from) Developing Diaphragm
The part of the ventral mesentery that extends from the liver to the ventral body wall is the ______ ______. The part between the liver and gut tube is the ______ ______.
- Falciform Ligament
- Lesser Omentum
________ are simply vertebrates with 4 legs
Tetrapods
________ allows the head to turn in feeding and vision.
A Neck
The outer covering of the body, also called skin
Integument
_______ _______ are converted into limbs
Paired fins
There is ____ benefit to being streamlined.
NO
With no water buoyancy, ______ must be strong with ______ more firmly related to the axial skeleton
appendages, girdles
What are the three functions of the skin?
- Physical protection
- Mechanical barrier
- Dissipation/Conservation of Heat (thermoregulation)
_______ and ______ circulation REPLACE gills
Lungs, pulmonary
The superficial layer of skin becomes ______ to resist drying and abrasion
CORNIFIED
________, _________, and a _______ must all be modified to function in air instead of water.
eyes, ears, nose
_________ and ______ had to be protected by ______ or _______ ______ to protect the embryo from dessication and mechanical damage and to receive metabolic wastes.
Eggs, embryos
Shells, Fetal membranes
What are the five functions of theintegument?
- Coloration
- Locomotion
- Respiratory exchange
- Energy storage
- Vitamin synthesis
Which class were the first Tetrapods?
Amphibians
resemble the first tetrapods
Quasi-terrestrial
________ are usually present and some respiration occurs through the lining of the mouth and throat
LUNGS
What is the basic morphological plan of the integumentary system?
- Multilayered epidermis
- Dermis
- Skin glands
- Ossification (development of bone)
_________ and _______moisten the eyes evolved of amphibians
Eyelids, Glands
The subclass of class Amphibia is __________. All other subclasses are EXTINCT.
LISSAMPHIBIA
- Most are less 30cm in length
- Possess a moist skin abundant glands and are only rarely with scales
- The outer layer cornified layer of skin is periodically shed
- Parts of the skeleton are commonly made of CARTILAGE
*
Subclass Lissamphibia
What subclass does the Order ANURA belong to?
Lissamphibia
Where does the bone form in SOME vertebrates? (i.e. what layer of skin)
Dermis
Label the Glands

- Sebaceous
- Sweat
What subclass does the order URODELA belong to?
Lissamphibia
characteristic of the order URODELA
having a tail
(Ex: salamanders)
What subclass does the Order APODA belong to?
Lissamphibia
Characteristics of the Order APODA?
without legs
obscure animals with primitive excretory organs and scales
(EX: CAECILIANS)
__________ are the 1st class to have all structures of amphibians that are necessary for fully terrestrial life, including _____ _____ and _______ resistant to drying (covered with HORNY SCALES)
Reptiles
fetal membranes, integument
Where do the epidermis and dermis derive from?
- Ectoderm
- Mesoderm
What are the layers of the epidermis? (All begin with STRATUM)
Nmemonic Device:
Can Linda Go Skating Granny?
- Corneum
- Lucidum
- Granulosum
- Spinosum
- Germinatum
Label the layers of the skin
- Lucid - clear
- Innermost layer, adjacent to dermal layer
- Granular
- Spindly
- Outermost layer - keratin is major component
- Lucidum
- Germinativum
- Granulosum
- Spinosum
- Corneum
Label the Parts of the Skin

- Stratum Corneum
- Stratum Lucidum
- Stratum Granulosum
- Stratum Spinosum
- Stratum Basale
- Keratinocyte
- Melanocyte
What is the deepest layer of skin next to the dermis, and what is the origination of its name?
Germinativum
Stratum = Layer
Germinativum = Germ Layer
(In the stratum germinativum) Daughter cells are produced here and pushed out to the surface, and transformed to become more _____ cells of the skin. What is the rate of production?
- Superficial
- Equal to the rate of loss at the surface of the epidermis
Most layers superficial to the Stratum Germinativum are ____ and contain either _____ cells or _____ cells.
- Secretory
- Mucous
- Proteinaceous
What am I?
- Some
- Produce different types of mucous
- Produce poisonous substances
- Are photophores (light-producing)
Mucous cells
These cells mainly produce keratin. They are also the main component of feathers, hair, claws, scales, and are also the dead outer layer of cells (in tetrapods) called the stratum corneum.
Proteinaceous Cells
The dermis is usually _____ than the epidermis
Thicker
The dermis is best developed in mammals. What does it primarily consist of?
- Connective tissue
- Nerves
- Smooth Muscle
- Blood Vessels
- Glands
- Fat
The result in the surface grooves and patterns on palms, soles, fingers, etc.
Dermal Papillae
What are pigment cells called?
Chromatophores
These cells have many irregular branching processes and have dispersable granules that are responsible for physiologic color changes.
Chromatophores
What are the four types of Chromatophores?
- Melanophore
- Erythrophore
- Xanthophore
- Iridiophore
Pigment cell that contains melanin - black/brown pigment
Melanophore
Pigment cell that contains red pigment
Erythrophore
Pigment cell that contains yellow pigment
Xanthophore
Pigment cell that produces silvery/iridescent skin
Iridiophore

Melanocytes
What are these an example of?

Iridiophores
What animal has the simplest chordate integument? Hint: It’s a protochordate
(Epidermis is one layer of columnar epithelial cells that secrete a cuticle - acellular layer. The dermis is thin with no pigment.)
Amphioxus
What are the skin layers for cyclostomata (lamprey and hagfish)?
Epidermis and Dermis
Where are the chromatophores in cyclostomata?
Dermis
What layer of cyclostomata skin am I?
Several layers that secrete a thin cuticle; No dead stratum corneum (the outer cells are living and have a nuclei)
Epidermis
Label the larval cyclostome

- Unicellular Gland
- Melanocyte
- Dermis
- Epidermis
- Canaliculi
What layer of fish skin am I?
There’s no dead stratum corneum and it’s thin with glandular elements
Epidermis
What layer of fish skin am I?
It’s embedded with dermal scales and has chromatophores (this includes iridiophores or guanophores that make the skin surface iridescent)
Dermis
The _______ _______ is more differentiated into regions and more firmly attached to the pelvic girdle than in amphibians
vertebral column
What are the characteristics of the class Reptilia?
- This group includes all animals that made the first TRUE invasion of land.
- Reptiles comprise the only class that is clearly ancestral to 2 other classes: BIRDS and MAMMALS
What are the subclass’s of the class Reptilia?
Subclass ANAPSIDA
Subclass DIAPSIDA
Subclass SYNAPSIDA
What does Anapsida mean?
an absence of openings in the bones that form the roof over the temporal region of the skull.
(most primitive in reptiles)
What Order is included in Subclass Anapsida?
Order TESTUDINES
(Turtles and Tortoises)
Characterisitics of the Order TESTUDINES
- Lacks temporal openings in the roof of the skull.
- Many specialized structures include:
–Shell, ribs, spine, toothless mouth, pectoral girdle.
Characteristics of the Subclass Diapsida
–A large group.
–These have either 2 temporal openings in the skull (diapsid) or are derived from having 2.
–All living reptiles except turtles.
–This lineage led to birds.
What 2 orders are apart of Subclass Diapsid?
Order SQUAMATA
(Lizards, Amphisbaenians, Snakes)
Order CROCODILIA
(Crocodiles and relatives)
Characteristics of Subclass SYNAPSIDA
–EXTINCT among reptiles.
–ONE temporal opening.
–A modified synapsid led to the CURRENT mammals.
What organism is apart of the Class AVES?
BIRDS
Characteristics of the Class AVES
•Birds have a high specialization of locomotor adaptation.
–All birds fly or are descendants of flyers.
–Birds are NOT very different from the particular reptiles they evolved from.
–Birds are the only vertebrate to combine FLIGHT with BIPEDALISM.
(Bipedalism is a form of terrestrial locomotion where an organism moves by means of its two rear limbs or legs)
What are the 2 subclass’s of the clas AVES?
Subclass ARCHAEORNITHES- extinct
Subclass NEORNITHES-all living birds
What are the characteristics of the Subclass ARCHAEORNITHES?
–EXTINCT
–Fully feathered, but had tail feathers arranged in a row along each side of a long lizard-like tail.
–The skull had large orbits and the beak-like rostrum was reptilian including having TEETH in its jaws.

Characteristics of the Subclass NEORNITHES?
–All remaining birds.
–Tail feathers are arranged like a fan at the end of the tail.
–There is fusion of bones in the spine, brain-case, lower leg, and “hand”
in the subclass NEORNITHES A system of ______ ______ is usually present, and air spaces are found within most bones.
AIR SACS
In the subclass NEORNITHES, Unless flightless (ex. Ostrich), the breastbone has a large ________
•This is where flight muscles have their origins.
KEEL
What are the 2 orders of subclass NEORNITHES?
–Superorder PALEOGNATHAE
(Ex: ostrich, emu)
•Mostly flightless.
–Superorder NEOGNATHAE - nearly all surviving birds.
What are the key characteristics to the class MAMMALIA?
–Hair or fur is present.
–Mammary glands are present.
–Single dentary bone on each side of the jaw.
•These may be fused to form a single dentary bone.
–3 ear ossicles (stapes, malleus, incus).
–Muscular diaphragm between pleural and abdominal cavities.
–Sweat glands.
–Heterodont teeth.
•2 sets of teeth, milk and permanent
–Enucleated, biconcave red blood cells.
–NO right 4th aortic arch
–Pinna (external ears)
–Well developed cerebral cortex.
What are the 3 subclasses of the Class MAMMALIA?
- Subclass PROTOTHERIA
- Subclass ALLOTHERIA - extinct
- Subclass THERIA
What order is included in the Subclass Prototheria?
Order MONOTREMATA
(Ex:Platypus and Echidna)
Characterisics of subclass Prototheria and Order Monotremata?
•OVIPAROUS - egg-laying.
–Unique among mammals
•Young are nourished by milk, presence of hair, and the single bone in the lower jaw qualify the monotremes as mammals.
Characteristics of the Subclass THERIA?
–All familiar mammals.
–VIVIPAROUS - give birth to live young
(separates them from Prototheria).
What are the 2 Infraclasses or the Subclass THERIA?
–Infraclass METATHERIA
–Infraclass EUTHERIA
What Order is included inside the Infraclass METATHERIA?
Order MARSUPIALIA
(Ex:Opossums, wombats, kangaroos, bandicoots)
Characteristics of Infraclass METATHERIA and Order MARSUPIALIA
Give birth to tiny embryonic young which are nourished in the pouch (MARSUPIUM) of the mother.
Characteristics of Infraclass EUTHERIA
–Placental mammals
–Many surviving orders
What 18 orders are included in the EUTHERIA Infraclass?
- Order INSECTIVORA (Shrews, Moles, Hedgehos)
- Order DERMOPTERA (Flying Lemurs)
- Order CHIROPTERA (Bats)
- Order PRIMATES (Lemurs, monkeys, apes, humans)
- Order CINGULATA (XENARTHRA) (anteaters, sloths, armadillos)
- Order PHOLIDOTA (scaly pangolins)
- Order LAGOMORPHA (Rabbits, Pikas)
- Order RODENTIA (Squirrels, beavers, rats, mice, porcupines)
- Order CETACEA (whales, dolphins)
- Order CARNIVORA (bears, dogs, raccoons, cats, hyenas)
- Order PINNIPEDIA (seals, sea lions, walruses)
- Order TUBULIDENTATA (Aardvark)
- Order PROBOSCIDEA (elephants)
- Order HYRACOIDEA (stocky hyraxes)
- Order SIRENIA (dugongs and mantees)
- Order ARTIODACTYLA ( pigs, camels, antelopes, cattle)
What are characteristics of the Order INSECTIVORA?
Small with numerous sharp teeth
What are the characteristics of the Order CHIROPTERA?
Only mammals capable of sustained FLIGHT
What are characteristics of the Order CINGULATA (XENARTHRA)?
simple teeth or no teeth
What are characteristics of the Order PHOLIDOTA?
Eats insects
What are characteristics of the Order RODENTIA?
Gnawing incisors
What are characteristics of the Order PERISSODACTYLA?
ODD-Toed
What are characteristics of the order ARTIODACTYLA
Even-Toed
__________ and _________ include most hoofed mammals and are collectively known as UNGULATES (Unguis = hoof)
Perissodactyla and artiodactyls
Mature sex cells are called______.
GAMETES
Gametes are _____ in the male and ______ (egg) cells in the female.
SPERM, OVUM
Each gamete carries a ______, or half-set of chromosomes
HAPLOID
The EGG Develops through the meiotic process of ________ (a reductional division).
OOGENESIS
Products of OOGENESIS are:
–OOGONIUM
–PRIMARY OOCYTE
–SECONDARY OOCYTE
–POLAR BODIES (3)
–OVUM (1)
•SPERM Develops through the meiotic process of _______ (a reduction division).
SPERMATOGENESIS
What are the products of spermatogenesis?
–SPERMATOGONIUM
–PRIMARY SPERMATOCYTE
–SECONDARY SPERMATOCYTE
–SPERMATID
–SPERMATOZOA
Sperm cells in vertebrates all have what 3 structures?
–HEAD - contains the nucleus.
•There are variable shapes in mammals, but all are capped by an ACROSOME.
–MIDDLE PIECE - contains mitochondria (provide energy).
–FLAGELLUM - moves the sperm cell around.
Egg cells can be classified based on the amount of _____ they have?
YOLK
______________ means it contains little yolk.
MICROLECITHAL
(Ex: amphioxus eggs may be ancestral chordate condition)
_______ means eggs contain moderate amounts of yolk.
MESOLECITHAL
- Includes most vertebrate eggs.
- Ex. Lampreys, chondrichthyes, fish, and amphibians.
_______ eggs contain large amounts of yolk.
MACROLECITHAL
Most fishes, reptiles, birds, and monotremes.
_________ mammals instead have a placenta to nourish the embryo and no longer need yolk.
EUTHERIAN
(Their eggs have returned to a MICROLECITHAL condition.)
________ a complex material made of proteins, phospholipids, and fats
YOLK
_______ _______ –yolk is concentrated toward this end of the egg.
VEGETAL POLE
_______ ______-the other end, a region of clearer cytoplasm and the nucleus.
ANIMAL POLE
Eggs with this asymmetrical distribution of yolk are called ___________ (“end + yolk”).
TELOLECITHAL
________ ________ tends to be highest at the ANIMAL pole (where clear cytoplasm and the nucleus are).
Metabolic activity
–If yolk is not asymmetrically distributed – ___________
ISOLECITHAL.
•Penetration of the egg by a sperm cell is a process involving both _______ (chemical) and ________ interactions between the sperm _________ and________.
ENZYMATIC, PHYSICAL
ACROSOME, EGG CORTEX.
Entry of the sperm into the egg restores the ________ number of chromosomes, and causes reactions within the egg that make it refractory to the entry of other sperm as well as initiating development of the embryo.
DIPLOID
the ZYGOTE begins to divide, Immediately after fertilization, so that at first there are ____, then ___, ___, ___, and ___ cells.
2,4,8,16,32
The dividing of the zygote immediately after fertilization is called ________.
CLEAVAGE
Since an increase in size does ______ accompany these divisions, the embryo is ____ _________ than the zygote was
NOT, NO LARGER
Cell division during this process is _______ , and each cell receives a full complement of chromosomes and genes
MITOTIC
________ - _________ division of the egg
_______ - Amphioxus, marsupials, placentals
_______ - primitive fish, amphibians
HOLOBLASTIC, TOTAL
EQUAL
UNEQUAL
_______-______ division of the egg
__________- advanced Osteichthyes, reptiles, birds, monotremes.
_________-arthropods
MEROBLASTIC, PARTIAL
DISCOIDAL
SUPERFICIAL
The ZYGOTE after CLEAVAGE is a multicellular embryo called a ________.
BLASTULA
The cavity in blastula is called the ____________ and occurs at different times in dfferent organisms.
BLASTOCOEL
Cavity (-coel) of the blastula (blasto-)
During cleavage, the individual daughter cells are called _________.
BLASTOMERES
•The process of cleavage, and the structure and shape of the blastula present are closely related to the ________ of _____ present.
AMOUNT, YOLK
–Cells that contain yolk are __________ to cleave than those that do not contain yolk.
SLOWER
In the chick embryo, there is an ________ amount of yolk and _________ is __________.
EXTENSIVE
CLEAVAGE, INCOMPLETE
The cells produced by cleavage form a ________ ________, which lies on top of the yolk.
GERMINAL DISK